Many of compounds out of indole derivatives are under development as medicines since they have a very interesting biological activity, or some compounds have already been used as medicines.
Such derivatives include a drug represented by a formula:
(wherein A and B represent at least one substituent including a hydrogen atom) which acts on each subclass of β-adrenergic receptor (WO96/16938, J. Med. Chem., 25, p. 670 to 679 (1982), British Patent No. 861,428 and the like). Carbon at a 2-position of a 2-aminopropane part bonded to a 3-position of an indole ring in these compounds is an asymmetric center, and plural stereoisomers originating therein can be present. However, specific isomers in these compounds are desirable in terms of a biological activity in many cases as commonly observed in biologically active substances. In actuality, a configuration at a 2-position in the part described above in a compound having a β3-adrenergic receptor stimulation which is described in WO96/16938 is preferably either R- or S-. Accordingly, if it is intended to provide the indole derivative described above having a configuration in which the 2-aminopropane part described above is 2(R) or 2(S), the final compound or the synthetic intermediate having the 2-aminopropane part described above has to be subjected to optical resolution.
On the other hand, proposed in WO96/16938 is a method in which formed from a corresponding amine compound is a part of:
and in which formed from a corresponding oxirane compound or carboxylic acid compound is a part of:
When employing such method, a desired optical isomer shall be able to be obtained as the final compound if the 2R- or 2S-isomer is used as the amine compound described above according to the purposes.